A dual function Y-cable (11pin to 5pin + 6pin), of which the 5pin (mini USB jack) is for charging/sync, and 6pin (ext USB jack) is for HTC's stereo headsets.

Note: Headset must have a 'left angled' or 'straight through' plug rather than right-angled if used at the same time in the Y Cable with the power cable. See your device accessory listings for suitable headsets.